Genetic Testing for Diabetes in Children

Diabetes is one of the most prevalent chronic diseases among children and adolescents, according to the Center for Disease Control and Prevention (CDC). The two types which affect that age group---type 1 and type 2---both carry an inherited predisposition to the disease. Scientists have made advancements in their genetic research, paving the way to more effective and accurate genetic testing.

Type 1

• Type 1 diabetes is an autoimmune disease in which glucose levels within the blood remain high because the pancreas is unable to produce insulin. Type 1 is the most common form of diabetes in children and adolescents.

Genetic Link

• The American Diabetes Association (ADA) states that the odds for developing Type 1 diabetes are roughly one in four to one in 10 when both parents have type 1. But a parent can have the gene---and pass it along to his child---without ever developing the disease himself. So even without an obvious family history, there can be a strong genetic risk.

  The National Institutes of Health's booklet, The Genetic Landscape of Diabetes, states that about 18 different regions of the genome---some containing multiple genes---have been linked to the development of type 1 diabetes.

Genetic Testing

• The ADA states that research into the genetics of type 1 diabetes thus far has shown that the disease is not inherited in a clearly dominant or recessive manner. Nor is a genetic risk enough to cause Type 1 diabetes in a child; there also has to be an external trigger, which the ADA identifies as possibly cold weather, diet or an infection. For these reasons, the ADA recommends screening children for diabetes risk only if the child has a parent or sibling with type 1 and intends to enter a diabetes prevention study that requires the genetic testing information.

Type 2 Diabetes

• With type 2 diabetes, there is a deficiency of insulin or the cells within the body do not respond properly to the insulin. The British Medical Journal (BMJ) reports that type 2 diabetes is a leading cause of morbidity and mortality in the developed world.

Genetic Link

• Obesity and hereditary are the main predictors of type 2 diabetes. According to the ADA, when both parents have type 2, the child has a 50 percent chance of developing the disease.

  In 2006, researchers from several international institutions discovered five areas within the genetic map that indicate a risk of developing the disease. Three years later, on Sept. 28, 2009, the UPI reported that scientists from Canada, France, the United Kingdom and Denmark had located a new gene which causes resistance to insulin; it is the first gene known to affect how insulin works, not how it is produced.

Genetic Testing

• In 2007, the Icelandic biotechnology company DeCode Genetics announced it had developed a genetic test for type 2 diabetes. Subsequent editorials from the BMJ, Wired Magazine and Public Library of Science concluded the test is only effective for a small proportion of those who are at risk for the disease, and thus did not recommend it.

  The BMJ summarized its editorial by saying, "scientists and the media are responsible for accurately and carefully interpreting the implications of studies of genetic associations for the benefit of the general public. Raising unrealistic expectations---even inadvertently---could distract attention from what can be done by applying what we already know to prevent diabetes and its complications."